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*Interesting discussion locally here in VK.
Is there any advantage in having the Copper ground rod surrounded by concrete over having the rod driven 6 feet straight into the earth? Hope this doesn't get too far off topic or develop into a prolonged discussion but I realised I didn't know the answer if there is one. 73 * -- *Gary* *Start the day off slow, then taper off.........* K3 #679 KPA500FT #18 KAT500FT 007 P3 #1629 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Hi Gary,
Interesting discussion. Depends on what type of soil, but as a general rule for lightning is much better with multiple rods deep into dirt (9ft +) with spacing distance between rods equal or bigger than the rod length. I've seen grounding installed close around a concrete structure cracking the concrete base on a direct hit. Many hams are literally pushing a 3ft rod into dirt, inefficient, my opinion is to prepare the grounding before and salt it periodically. Here is a good document, is a must to be read for the ones with lightning activity. http://members.rennlist.org/warren/ground.pdf vy73 de VE3GNO Daniel ________________________________ From: Gary Gregory <[hidden email]> To: Elecraft <[hidden email]> Sent: Monday, September 10, 2012 6:30:52 PM Subject: [Elecraft] Ground Rods *Interesting discussion locally here in VK. Is there any advantage in having the Copper ground rod surrounded by concrete over having the rod driven 6 feet straight into the earth? Hope this doesn't get too far off topic or develop into a prolonged discussion but I realised I didn't know the answer if there is one. 73 * -- *Gary* *Start the day off slow, then taper off.........* K3 #679 KPA500FT #18 KAT500FT 007 P3 #1629 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net/ Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Gary Gregory
Gary,
As far as I know, the conductivity of earth and concrete are quite similar, so it should make little difference. 73, Don W3FPR On 9/10/2012 6:30 PM, Gary Gregory wrote: > *Interesting discussion locally here in VK. > > Is there any advantage in having the Copper ground rod surrounded by > concrete over having the rod driven 6 feet straight into the earth? > > Hope this doesn't get too far off topic or develop into a prolonged > discussion but I realised I didn't know the answer if there is one. > > 73 > * ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by VE3GNO Daniel
Yes, interesting subject. I did a different approach with the new house. The main drain line for the roof water had to be in a trench and because of the elevation, it had to be DEEP so when the drain lines were put in I included two separate #4 copper lines. Total feet 200+.
All station grounds are with copper strap from a common point in the basement to the operating position. Up 10 feet. All else is locally grounded with rods as necessary. I only point this out for those who are building a new home. THINK RADIO. Cheers, Mel K6KBE --- On Mon, 9/10/12, VE3GNO Daniel <[hidden email]> wrote: From: VE3GNO Daniel <[hidden email]> Subject: Re: [Elecraft] Ground Rods To: "Gary Gregory" <[hidden email]>, "Elecraft" <[hidden email]> Date: Monday, September 10, 2012, 4:18 PM Hi Gary, Interesting discussion. Depends on what type of soil, but as a general rule for lightning is much better with multiple rods deep into dirt (9ft +) with spacing distance between rods equal or bigger than the rod length. I've seen grounding installed close around a concrete structure cracking the concrete base on a direct hit. Many hams are literally pushing a 3ft rod into dirt, inefficient, my opinion is to prepare the grounding before and salt it periodically. Here is a good document, is a must to be read for the ones with lightning activity. http://members.rennlist.org/warren/ground.pdf vy73 de VE3GNO Daniel ________________________________ From: Gary Gregory <[hidden email]> To: Elecraft <[hidden email]> Sent: Monday, September 10, 2012 6:30:52 PM Subject: [Elecraft] Ground Rods *Interesting discussion locally here in VK. Is there any advantage in having the Copper ground rod surrounded by concrete over having the rod driven 6 feet straight into the earth? Hope this doesn't get too far off topic or develop into a prolonged discussion but I realised I didn't know the answer if there is one. 73 * -- *Gary* *Start the day off slow, then taper off.........* K3 #679 KPA500FT #18 KAT500FT 007 P3 #1629 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net/ Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Gary Gregory
Gary there are many factors effecting ground systems. In general concrete is
fairly conductive year round but earth conductivity is highly dependent on the type of soil and its moisture content. Many a user of ground return telephone systems found out clay soil in the summer could make you sound a million miles away. Grounding systems for the shack may need to fulfill multiple functions and those functions are often at cross purposes. The impedance of an un-terminated transmission line inverts every quarter wave so connectors to ground rods used in RF systems can be completely useless if they are more than a fraction of a quarter wave in length. Likewise the vertical connectors to earth grounds from 2nd floor shacks can become unwanted radiating parts of your antenna system. Such problems do not negate the effectiveness of such ground systems for arresting lightning. Lightning does not like to make sharp turns so in general the shortest, most direct path to earth ground, will be the best lightning ground and the further away from your shack the better. This suggests that combination of a RF ground and lightning protection grounds is really a series or combination of grounds. Quantity prevails over quality. Fortunately I live in California where lightning is the exception rather than the rule so I design a good RF ground and let it go at that. 73 Fred, AE6QL -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Gary Gregory Sent: Monday, September 10, 2012 3:31 PM To: Elecraft Subject: [Elecraft] Ground Rods *Interesting discussion locally here in VK. Is there any advantage in having the Copper ground rod surrounded by concrete over having the rod driven 6 feet straight into the earth? Hope this doesn't get too far off topic or develop into a prolonged discussion but I realised I didn't know the answer if there is one. 73 * -- *Gary* *Start the day off slow, then taper off.........* K3 #679 KPA500FT #18 KAT500FT 007 P3 #1629 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Gary Gregory
> -----Original Message-----
> From: Gary Gregory > Subject: [Elecraft] Ground Rods > > ...Is there any advantage in having the Copper ground rod > surrounded by concrete over having the rod driven 6 feet > straight into the earth? ... In my limited experience, lightning + ground rod in concrete = BOMB. Of course, lightning can turn just about anything into a bomb. Chuck N4XS ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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